Coated staple and fastening tool for the same

ABSTRACT

Insulated or coated staple and a fastening tool for driving the same into a substrate. The tool includes a housing and a driver reciprocally mounted in the housing and moveable with respect to the housing, the driver having a driving surface for engaging a fastener such as a coated staple. A magazine assembly is associated with the housing for positioning and aligning the coated fastener in the path of the driver so that when actuated, the driver strikes the fastener and forcibly ejects it from the magazine into the substrate on which the object to be fastened is to be secured. Suitable fasteners include coated staples (of various sizes and configurations), nails, brads, rivets, etc.

This application is a continuation of U.S. Ser. No. 10/017,746 filed onDec. 7, 2001, the disclosure of which is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

The present invention is directed towards a coated staple and a staplegun or fastener driving or applying tool for driving such staples intosurfaces.

Staple, nail, brad, screw and other fastener-driving applying tools forindustrial, commercial and do-it-yourself (DIY) use are well known.Often such tools are used to secure cables, wires, tubing and the liketo a substrate such as wood by driving the fastener into the substrate,the fastener thereby surrounding the cable, wire or tubing on threesides. However, the fastener being applied may at the time ofapplication (due to the impact of the fastener) or subsequently (due towire and/or substrate expansion or contraction over time) penetrate,damage or deform the item being fastened, resulting in an electricalshort circuit, leak or other deleterious effect.

It is often desirable to secure wire or cable, including withoutlimitation high speed transmission multimedia cable and wire (such asCAT-5 and RG6) and NM Building Wire (also known as “Romex” wire), tosubstrates using staples and so-called insulators. The use of theseso-called insulators, which may also provide a cushioning function,minimizes the possibility that the staple will penetrate, damage ordeform the sheathing on the wire and cause an electrical short or changein current. The use of pro-assembled individual staples and insulators,installed by means of a hammer or similar implement, is conventional.However, this method is slow, tedious, and not very precise.

Attempts to improve the efficiency and standardization of the currentprocess have largely focused on use of hand powered cable tackerstaplers to install collated and cohered pre-assemblies of staples andso-called insulators. Each individual assembly of a staple and insulatorhas tended to be similar in essential form to the hammer-appliedassemblies now widely employed. These attempts have proved to beinadequate and unsuccessful because they either do not install thestaple/insulator assemblies in a manner which meets industryrequirements for staple holding power (such as those described in ULspecifications) for a wide range of wire types and diameters used intypical residential and commercial construction, or the cable tackerstaplers used require too much hand pressure or too broad a range ofhand motion for the average user to comfortably operate them so thatthey install the assemblies in accordance with such industryrequirements. In addition, the quantity of staples/insulators that fitin a typically sized magazine is small, resulting in frequent reloading.This type of staple/insulator assembly is also relatively expensive.

It is therefore an object of the present invention to provide animproved insulated or coated fastener which helps minimize or eliminatethe possibility that the fastener penetrates, damages or deforms thesheathing of the wire being fastened.

It is a further object of the present invention to provide an improvedfastener driving tool or gun that ensures consistent, uniform andreproducible driving depth of the fastener into the substrate.

It is a still further object of the present invention to provide afastening device that automatically and repeatably drives insulated orcoated fasteners to a predetermined depth into a substrate to secure anobject therein.

It is a still further object of the present invention to provide afastener gun driven insulated or coated fastener which is relativelyless expensive than those currently in use.

It is a still further object of the present invention to provide asystem of a fastening device and a more compact insulated or coatedstaple or fastener which requires less frequent reloading.

SUMMARY OF THE INVENTION

The problems of the prior art have been overcome by the presentinvention, which provides an insulated or coated staple and a fasteningtool for driving the same into a substrate. The tool includes a housingand a driver reciprocally mounted in the housing and moveable withrespect to the housing, the driver having a driving surface for engaginga fastener such as a coated staple. A magazine assembly is associatedwith the housing for holding one or more coated fasteners, and forpositioning and aligning a coated fastener in the path of the driver sothat when actuated, the driver strikes the fastener and forcibly ejectsit from the magazine into the substrate onto which the object to befastened is to be secured. Suitable fasteners include coated staples (ofvarious sizes and configurations), nails, brads, rivets, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a fastening tool in accordance with thepresent invention;

FIG. 2 is a front or back view of the drive blade in accordance with thepresent invention;

FIG. 3 is a front view of the drive blade and nose piece in accordancewith the present invention;

FIG. 4 is a front or back view of the staple in accordance with thepresent invention; and

FIG. 5 is a side view of the staple of FIG. 4 in accordance with thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Turning first to FIG. 1, there is shown one embodiment of the presentinvention, which is a spring actuated staple gun adapted to driveU-shaped staples housed in a magazine into a surface or substrate. Thegun includes a tool body 1 comprised of two stamped nickel-plated sheetmetal sides 1A and 1B that form a housing there between. Alternatively,the housing could be a molded body. Pivotally fixed to the underside ofa handle 2 is a spring-loaded lever assembly C, substantially located insaid housing, which includes extended link 2A and lifter 2C and allowsthe handle of the gun to be cocked and uncocked in order to actuate thegun. A handle return spring 9 is fixed to the handle 2. Spring retainer8 has opposite flanges 8A, 8B that align with opposite slots 5A′ 5B′ insides 1A and 1B of the tool body 1 to fix spring retainer 8 therein. Adriver spring pad 5 aligns with the bottom of the driver spring 6 andsits in the body of drive blade assembly 4. Impact pad 13 has an impactledge 14 that aligns with opposite slots 14A and 14B in sides 1A and 1Bof the tool body 1 to fix the same in the housing, and thereby limit thedownward movement of driver blade assembly 4 a predetermined amount bypreventing the seat 4A of drive blade assembly 4 from extending past thesurface of the impact pad 13. The impact pad 13 thus affects thelocation of the bottom H of the drive blade in the “rest” (down)position as it relates to the top of the tunnel in the nose piece 3, andthereby prevents the drive blade from driving the staple too tightlyover the wire regardless of the wire diameter. Nose piece 3 secures overthe drive blade assembly 4 as is conventional in the art. Magazineassembly 15 combines with pusher assembly 16 to selectively provide thesupply of fasteners into the path of the driver blade.

Pressing downward on the handle 2 first causes a pair of opposite lipsL, L′ of lifter 2C, which lips engage the drive blade assembly 4, tolift the drive blade assembly 4 upward against the bias of driver spring6. Further downward pressure of the handle 2 causes the lips L, L′ torelease from the drive blade assembly 4, thereby causing the driverspring 6 to force the drive blade assembly 4 downward. The downwardforce imparted to the drive blade assembly 4 by the spring 6 causes thehead H of the drive blade assembly to strike a staple located at theforwardmost end of the magazine assembly 15 and in the path of the driveblade, and drive the staple into the work surface below. Those skilledin the art will recognize that other ways to actuate the drive blade,including any stored energy source (such as leaf springs, torsionsprings,. electricity, hydraulics and compressed gas (e.g. air)) can beused.

Turning now to FIGS. 2 and 3, the details of the modified drive bladeare shown. The head H of the drive blade 4 is configured to correspondin shape to the top (or crown) portion of the staple 53, and theradiused transitional areas (shoulders) 56 which join the crown to thestaple legs 51,52, so that upon impact, the drive blade 4 squarelyengages the staple crown and shoulder portions and forces the staplestraight out of the tool and into the substrate. Thus, the centerportion of the head H is recessed slightly, with spaced opposite tips57, 58 extending lower than the recessed portion, and being radiused asshown. The length of the blade 4 is predetermined and depends in part onthe length of the staple and the characteristics of the substrate intowhich the staple is being driven, so that the staple does not penetrateinto the substrate too deeply. Typical substrates include standard woodbuilding materials used in studs, joists, rafters, etc. Nose piece 3secures over the drive blade 4. At its sides, the nose piece 3 extendsbelow the drive blade as shown in FIG. 3. A U-shaped notch 30 is carvedout of the bottom of the nose piece 3. This notch 30 provides areceptacle and guide for the wire or other object to be fastened to bepositioned relative to the staple gun. The bottom of the drive blade 4at rest is level with the top of the notch 30 of the nose piece 3. Thislevel orientation of the drive blade 4 and notch 30 is critical toinsuring that the staple gun does not drive the fastener too deeply,thereby possibly crushing, damaging or deforming the object to befastened. This relationship also prevents damage to the object if thestaple gun is fired on a cable without staples in the magazine. Thisdistance may vary, based on varying the thickness of the crown portionof the fastener.

Turning now to FIGS. 4 and 5, the insulated or coated staple of thepresent invention is shown. The staple 50 is generally U-shaped, andincludes two parallel or substantially parallel vertically extendinglegs 51, 52, joined by crown 53 and radiused shoulder portion 56. Thecrown portion 53 is substantially flat, with radiused shoulder areas 56leading to the parallel legs 51, 52. Preferably the free end (point) ofeach staple leg 51, 52 terminates, through an angled cut 57, in a sharpedge (point) 55 to facilitate penetration into the substrate. Also,preferably, the angle cuts 57 to the points 55 are mirror images of oneanother (as shown). These mirror image angle cuts 57 cause the staplelegs to move in opposite directions upon penetration into the substrate,making the staple more difficult to extract from the substrate,resulting in additional holding power of the staple. The degree of anglecut will vary based on the application, and will be easily determinableby one well versed in the art of staple manufacture. An angle cut of 45°has been found to be suitable for this application.

The coating for the staple 50 is made of a material that is insulatingand/or cushioning and forms a strong bond with the base metal of thefastener or staple. Suitable base metals include, without limitation,bright steel and galvanized steel. The coating material cannot be toobrittle, or it will tear during the staple forming process. It ispreferred that the coating material be different from the wire material.Nylon , or plastics containing nylon material, including withoutlimitation polyacetal, polymide, polycarbonate, polyethylene,polypropylene, polyurethane, polyvinylchloride, polyvinylidene fluoride,and blends and combinations thereof, are particular preferred for thecoating. Coating with nylon provides insulation. It also provides,depending upon the thickness of the coating, cushioning so that uponimpact of the staple with the wire or cable being fastened, the wire iseven less likely to be crushed, damaged or deformed, which could causeshort circuits or other deleterious effects on the electrical currentbeing transmitted. In addition, penetration of the staple leg 51,52 intothe substrate causes the wood fibers adjacent to the staple leg 51,52to, in effect, act as barbs in the coating material, thereby making thestaple leg more difficult to extract, thereby resulting in additionalholding power. Preferably the coating is of a uniform thickness of froma minimum of about 1000 mils to a maximum that will vary based on thestaple leg length, the dimension of the article to be attached to thesubstrate, and the substrate into which the article is to be attached.In the current application this maximum thickness has been found to be0.050 inches. A thickness of from about 0.001 inches to about 0.010inches is preferred. Preferably all of the staple, or at least theportion contacting the wire or other item to be attached, is coated,although the faces 57 of angled edges of each leg 51, 52 may be devoidof coating since they are formed by cutting the wire after it is coated.The coating adheres to the wire and forms an integral unitary structure.Although the staple wire and coating perform different functions (e.g.,the wire staple provides strength while the coating provides holdingpower in the substrate and has electrical insulating properties whilealso providing a protective barrier to prevent the wire staple materialfrom damaging the electrical wire being stapled), the adhesion of thecoating on the wire is such that the coating does not engage insubstantial independent movement relative to the wire once the coatingis adhered, even upon application of the fastener in the substrate. Suchindependent movement would adversely affect the functioning of thefastener.

The coating can be extruded onto the wire prior to the staple-formingprocess. The coating can also be applied by spraying, dipping or otherprocesses well known to those versed in the art of wire coating. Thebase wire (e.g., galvanized steel) is made first using conventional wiredrawing processes, and then the coating (e.g., nylon) is applied aroundthe wire in a subsequent process.

Other suitable coatings include, without limitation, dielectricmaterials such as thermoplastic elastomers, including polyethylene,polypropylene, polybutylene, PVC, CPVC, nylon, ABS and PVDF, with nylonbeing preferred.

In view of the dimension of the coating, the staples can be accommodatedby conventional staple tacker gun magazines with little or nomodification thereof. Any modifications deemed necessary to accommodatethe increased outer width and decreased inner width of the stapleresulting from the coating are generally well within the skill of thoseversed in the art of staple tacker gun manufacture.

The staple gun of the preferred embodiment of the present invention isadapted to drive U-shaped staples (releasably interconnected in thestaple magazine) into a substrate in order to secure an object such aswire, cable or tubing to the substrate.

Those skilled in the art will recognize that any stored energy sourcecan be used to actuate the driver of the fastening tool, including,without limitation, mechanical means, compressed air, electric means,hydraulics, etc.

In operation, the fastening tool of the preferred embodiment of thepresent invention is used as follows. First, cohered cores of articlessuch as fasteners (e.g., insulated or coated staples) are loaded intothe magazine. Staples in these cores are preferably cohered in aside-by-side relation. The tool is then aligned over the object to befastened. Upon actuation of the driver, fasteners are expelled from themagazine, one at a time, around the object to be fastened on three sidesand into the substrate. The staple pusher in the magazine assemblyautomatically urges the next article (e.g., coated staple) into axialalignment with the drive path to be expelled by the next complete drivestroke.

1. A fastening tool and at least one fastener, said tool comprising: ahousing; a driver associated with said housing; an actuator foractuating said driver; means for holding at least one fastenerassociated with said housing, said means for holding said at least onefastener containing at least one individually, coated fastener formedfrom uniformly coated material, including a forwardmost fastener; meansfor aligning one of said at least one fastener with said driver.
 2. Thefastening tool and at least one fastener of claim 1, wherein said toolis adapted to fasten an object to a substrate.
 3. The fastening tool andat least one fastener of claim 1, wherein said fastener is a staple. 4.The fastening tool and at least one fastener of claim 2, wherein saidobject to be fastened to a substrate is a wire.
 5. A fastener which: isformed from a uniformly coated material, which coating remains uniformonce cured and remains on the fastener after it is formed; comprises abight portion and a pair of legs extending from said bight portion, eachleg terminating in a free end.
 6. The fastener of claim 5, wherein saidfastener is a staple.
 7. The fastener of claim 5, wherein said fasteneris for securing an object to a substrate.
 8. The fastener of claim 6,wherein said fastener is for securing an object to a substrate.
 9. Thefastener of claim 7, wherein said object is a wire.
 10. The fastener ofclaim 8, wherein said object is a wire.
 11. The fastener of claim 5,wherein said coating and said fastener form an integral unitarystructure.
 12. The fastener of claim 6, wherein said coating and saidfastener form an integral unitary structure.
 13. The fastener of claim5, wherein said coating has a thickness of from about 0.001 inches toabout 0.050 inches.
 14. The fastener of claim 6, wherein said coatinghas a thickness of from about 0.001 inches to about 0.050 inches. 15.The fastener of claim 5, wherein the coated material is bright orgalvanized steel.
 16. The fastener of claim 6, wherein the coatedmaterial is bright or galvanized steel.
 17. The fastener of claim 5,wherein each said free end terminates in an angled cut to facilitatepenetration into said substrate.
 18. The fastener of claim 5, whereinsaid coating is selected from the group consisting of nylon,polyethylene, polypropylene, polybutylene, PVC, CPVC, ABS and PVDF. 19.The fastener of claim 6, wherein said coating is selected from the groupconsisting of nylon, polyethylene, polypropylene, polybutylene, PVC,CPVC, ABS and PVDF.
 20. The fastener of claim 5, wherein said coating isnylon.
 21. The fastener of claim 6, wherein said coating is nylon.
 22. Amethod for forming a fastener, comprising: providing a material with auniform coating thereon, which coating remains uniform when cured; andforming said material into a staple body with a bight portion and a pairof legs extending from said bight portion, each leg terminating in afree end.